Someone able to ID some parts for me?

[pancakeplease]

I ordered a O2 headphone amplifier but for my speakers I've been using an older Denon receiver. It's about 11 years old but the sound coming out of both the headphone out and my speakers are NOTICEABLY better than my newer Onkyo receiver with all the HDMI, features, etc. Granted, the Denon was $1000 and the Onkyo is a $500 at most receiver, I'm still curious to know what is creating the difference in sound quality.

I'm not a DIYer and I don't know anything about electronics. I only recently googled what a resistor was to order parts to make my own Cmoy amp. lol


I took some pictures of my receiver opened up and have followed up with close-up pictures of each section/board.

Could someone ID the amp and DAC on this receiver and tell me what the quality is like? I've been looking on the boards to see if there's something I recognize... and I don't. Maybe DIYers will see some parts here and know a thing or two about it.

The main reason I want to know is because I'd like to know exactly how much I'd be upgrading my getting a desktop headphone amplifier or a speaker amp. Based on reviews, the O2 headphone amp should be miles better than the onboard headphone out on this receiver but I don't know enough about electronics to know.




Here are some pictures. I can definitely read off parts, serial numbers and get close ups. Any ID will help.


Opened up:

An externally hosted image should be here but it was not working when we last tested it.

Upper left corner. Speaker outs
[IMG=http://img803.imageshack.us/img803/6792/imag0342c.jpg][/IMG]

 

[pancakeplease]

Sorry the post got submitted before I finished.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

I'm guessing one of these chips are the DAC?

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

Headphone out:

An externally hosted image should be here but it was not working when we last tested it.

 

[jaycee]

The difference is most likely that the Denon is class AB and the Onkyo is most likely Class D.

It'd be better to link straight to your ImageShack profile

 

[pancakeplease]

Yeah I'm having some trouble with the pictures.

Here's the album with all the pictures of the receiver's insides. I can't tell which part is the DAC or amp chip, etc. cause I'm totally electronics ignorant.

Is there a way to know what class this receiver is? Does it usually say this in the manual or is this something that can only be found from looking inside and IDing the parts?

 

[abraxalito]

Granted, the Denon was $1000 and the Onkyo is a $500 at most receiver, I'm still curious to know what is creating the difference in sound quality.

Could be exactly as jaycee says, or if both are using AB amps then I'd reckon it would be down to the different levels of noise. With more modern digital electronics, the feature sizes are smaller and this leads to higher speeds, meaning more RF and at higher frequencies.

The main reason I want to know is because I'd like to know exactly how much I'd be upgrading my getting a desktop headphone amplifier or a speaker amp. Based on reviews, the O2 headphone amp should be miles better than the onboard headphone out on this receiver but I don't know enough about electronics to know.

I think the sound quality will depend to the greatest extent on how well you can keep the receiver's noise out of the O2. Given a noise-free environment the O2 I'd expect to be fairly transparent, but receivers which contain HDMI stuff aren't exactly too benign. If you're interested in experimenting, try getting a decent quality line transformer to put between the receiver and external amp.

 

[pancakeplease]

Okay actually I think I figured out what to look for. Black little rectangles that are chips.


Here are some numbers.

CS492604-CL
Found out this is a multi decode. CS492604-CL pdf, CS492604-CL description, CS492604-CL datasheets, CS492604-CL view ::: ALLDATASHEET :::


NJU7313AL
Analog function switch
NJU7313AL datasheet pdf datenblatt - New Japan Radio - ANALOG FUNCTION SWITCH?? ::: ALLDATASHEET :::

TC9459N
Electronic volume control
TC9459N Datasheet pdf - ELECTRONIC VOLUME CONTROL - TOSHIBA
There's 3 of these chips.


74HCT157
Multiplexer
74HCT157 Datasheet pdf - Quad 2-input multiplexer - Philips


AD1855JRS
Stereo, 96 kHz, Multibit DAC - Analog Devices
AD1855JRS datasheet pdf datenblatt - Analog Devices - Stereo, 96 kHz, Multibit DAC ::: ALLDATASHEET :::
There are 3 of these chips.

ZR38601PCQ
Programmable digital audio processor
ZR38601 pdf, ZR38601 description, ZR38601 datasheets, ZR38601 view ::: ALLDATASHEET :::


VHC123A
Dual Monostable Multivibrator
VHC123A datasheet, VHC123A datasheets, VHC123A datenblatt, VHC123A manual, VHC123A data sheets, VHC123A pdf - ALLDATASHEET.COM


LV14A
Texas Instrument HEX SCHMITT-TRIGGER INVERTERS'
LV14A datasheet, LV14A datasheets, LV14A datenblatt, LV14A manual, LV14A data sheets, LV14A pdf - ALLDATASHEET.COM


AK5351VF
Enhanced Dual bit 20bit ADC
http://www.alldatasheet.com/view.jsp?Searchword=AK5351VF

LC89055W
Digital Audio Interface Receiver
LC89055W datasheet, LC89055W datasheets, LC89055W datenblatt, LC89055W manual, LC89055W data sheets, LC89055W pdf - ALLDATASHEET.COM


LV00A
QUADRUPLE 2 INPUT POSITIVE NAND GATES
LV00A datasheet, LV00A datasheets, LV00A datenblatt, LV00A manual, LV00A data sheets, LV00A pdf - ALLDATASHEET.COM

TC9372N
ANALOG SWITCH ARRAY ICs - Toshiba Semiconductor
TC9273N datasheet pdf datenblatt - Toshiba Semiconductor - ANALOG SWITCH ARRAY ICs ::: ALLDATASHEET :::


TC9274N
ANALOG SWITCH ARRAY ICs - Toshiba Semiconductor
http://www.alldatasheet.com/datasheet-pdf/pdf/32131/TOSHIBA/TC9274N.html

MP93CS45F
Quality And Reliability Assurance / Handling Precautions - Toshiba Semiconductor
TMP93CS45F datasheet pdf datenblatt - Toshiba Semiconductor - Quality And Reliability Assurance / Handling Precautions ::: ALLDATASHEET :::


BU4052BC
Dual 4-channel analog multiplexer / demultiplexer - Rohm
BU4052BC datasheet pdf datenblatt - Rohm - Dual 4-channel analog multiplexer / demultiplexer ::: ALLDATASHEET :::

MC74HC4053N
Analog Multiplexers/Demultiplexers Motorola
MC74HC4053N Datasheet pdf - Analog Multiplexers/Demultiplexers - Motorola


Those are most of the chips. I left something else out called Hex buffer and the duplicates like the BU4052BC chip. There's like 5 or 6 of those.



So there are 3 DAC chips.



What is the quality of the onboard DAC and will I benefit from getting a standalone DAC? Or is it good enough?

How good is the amplifier? What about headphone out? Do any of these parts reveal such information?

 

[Enzo]

I like to preach, "it's the circuit, not the parts" when my guys ask if changing this part or that will improve the sound. Obviously an oversimplification, but still makes a point. You can replace every part in it with a "better" part, but that doesn;t change the circuit. A more marginal design will remain a more marginal design.

One design might have intended the phones amplifier to sound good, while the other might be a throw-away circuit just to have a phones jack, but not really care how it sounds. I have worked on many cheap consumer CD decks that had weak phones drivers that sucked. A receiver intended for high quality phones listening will be very different from a receiver intended for "home theater" but including a phones jack for watching loud movies while the family sleeps in the other room. Or if you have ever worked in radio, the "cue" amp need not be real hifi.

Rather than lots of photos of parts, I think to the technical among us, the schematics tell a much better tale. For example, in some amps the headphones are driven from the main speaker outputs, in other amps the phones have their own little amp. Then you have to decide even if they are separate, are they using the same audio signal source, or do they each have their own decoder. seems unlikely to me they have a separate DAC for phones, but then I don't work on consumer audio enough to know what is common.

 

[jaycee]

The AD1855 DAC is a very good audio DAC.

As for you benefitting from a standalone DAC, hard to say. I would lean toward yes, simply because the design will focus on getting the best D-A performance and the best quality headphone output, whereas the Denon has to do a lot. You may not notice it though.

 

[poynton]

...........................It'd be better to link straight to your ImageShack profile

Absolutely not !!!!
Unless such links are continually refreshed, they disappear.
Also, they tend to be very large and take ages to download for many members not on fast internet.

Yeah I'm having some trouble with the pictures. .......................

If you go to the "advanced reply", pictures are actually very easy to upload as jpegs or .png.
Thet come up as pictures as large and detailed as those posted on photobucket etc..


See ...http://www.diyaudio.com/forums/everything-else/183084-pictures-why-not-attach-them.html



Andy


/rant off

 

[Mooly]

I ordered a O2 headphone amplifier but for my speakers I've been using an older Denon receiver. It's about 11 years old but the sound coming out of both the headphone out and my speakers are NOTICEABLY better than my newer Onkyo receiver with all the HDMI, features, etc. Granted, the Denon was $1000 and the Onkyo is a $500 at most receiver, I'm still curious to know what is creating the difference in sound quality.

Hmmm...

Welcome to the world of high quality audio reproduction.
You have been able to identify that one receiver sounds better than the other... the start of a slippery slope

It all down to the circuitry (and the overcomplication of such).

A simple 5 or 6 transistor amplifier could blow these two out of the water on sound reproduction.

 

[pancakeplease]

Haha thank you guys. The receiver does sound great so I guess whatever Denon did with its stuff, they did it right. Kind of sucks that it's not really like a computer where you can just read specs and know which ones better. Makes upgrading or "upgrading" a bit difficult especially since there's no auditioning equipment.